--- a/sys/dev/raid/hptmv/entry.c
+++ b/sys/dev/raid/hptmv/entry.c
@@ -2625,8 +2625,13 @@
 static void
 hpt_timeout(void *arg)
 {
-	_VBUS_INST(&((PBUS_DMAMAP)((union ccb *)arg)->ccb_adapter)->pAdapter->VBus)
-	lock_driver();
+	union ccb *ccb = (union ccb *)arg;
+	_VBUS_INST(&((PBUS_DMAMAP)ccb->ccb_adapter)->pAdapter->VBus)
+	if (lockmgr(&driver_lock, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
+		/* avoid AB-BA with callout_stop() under driver_lock */
+		callout_reset(ccb->ccb_h.timeout_ch, hz, hpt_timeout, arg);
+		return;
+	}
 	fResetVBus(_VBUS_P0);
 	unlock_driver();
 }